Quote from: bronan on October 21, 2011, 10:47:59 AM

Quote from: Shevek on October 18, 2011, 01:16:40 PM

Quote from: deslok on October 15, 2011, 08:06:10 PM

Quote from: pinarphan on October 15, 2011, 07:56:53 PM

How strong of a power supply is needed?

That depends on the age of the machine (a pentium 4 is also very demanding) but for a single 58xx card usually a 400-500 watt psu has a sufficently sized 12v rail, one like this is on the lower end of the spectrum it would handle a single 58xx or a pair of 57xx without too much trouble http://www.newegg.com/Product/Product.aspx?Item=N82E16817182202

Be careful with PSU: I've recently bought a 650W one for one 5850 and it gave most of the power to the 5V, 3.3V lines and only a small fraction to 12V. So it was useless for my mining purposes.

Now this is what i found out myself with a brand new enermax 530w 85+, would you believe it can not handle 2 low power cards in a low power consuming machine.. By low power i mean a 75 w gt440 and a 116 w gts450
It simply can not handle the load (the system without the cards uses 106w on his internal gpu)
Every time i add the gt440 the system began to crash and constant went into bleu screens, with power failure messages on the cpu.
I put in my old trusty ocz 700w and no more crashes or problems at all, so somehow it seems that the powersupply are not really giving the power they should, ofcourse i would like to use the high efficient psu because the old power supply probably consumes much more power to give a similar output. So for me enermax is not a good choice anymore
Especially since the shop returned the supply to me stating there was nothing wrong with it and send me a bill for 65 euro testing costs.

You always absolutely always need to check the rail configuration before buying a power supply, for mining look for single rail power supplies and make sure the majority of the capacity is on the 12v not 5v rails. older designs will still have the majority of their amperage on the 5v rail